4 Services from otp.openverbs.com

Verifies a submitted TOTP code against a base32 secret with configurable clock-drift tolerance, returning whether the code is valid and the matching time-step offset.

Builds an otpauth:// URI (used in authenticator QR codes) for a given TOTP or HOTP secret, with label, issuer, algorithm, digits, and period/counter.

Generates an RFC 6238 time-based one-time password (TOTP) from a base32 secret, returning the code, counter, and seconds remaining in the window.

Generates an RFC 4226 counter-based HMAC one-time password (HOTP) from a base32 secret and counter value